This invention concerns a method of welding two halves of a hollow ceramic component before sintering, yielding a tight-toleranced monobloc part which remains monolithic even after sintering.
It also concerns a welding machine serving to implement said method.
There are several known methods of welding or bonding together hollow ceramic component halves. However, none of these methods are entirely satisfactory for obtaining very close tolerance monobloc components.
The known method known as "mirror" bonding, which consists in applying each component half to a face of a heating plate, does not provide a true weld in the sense that the parts are merely stuck together when the plastic binders contained in the ceramic material migrate toward the surface of the joining plane as each half-component is applied to the "mirror" and then bonded plastic-to-plastic as the parts are joined. This weld is destroyed when the weld slag is chipped off.
The method of welding with a solvent, whether in pure or slipped form, yields mediocre results, for the weld has many defects after sintering. Moreover, the use of solvents requires a number of safety precautions.
Ultrasonic welding provides a good weld of the two half-components, but nevertheless has three major drawbacks, namely:
it does not allow more than one component to be welded per machine and per cycle; PA1 welding time is very long, lasting about 20 seconds; PA1 and a new sonotrode must be fabricated every time there is a change in part geometry.